Introduction

This opening chapter introduces the study’s central research puzzles, namely why so many joined the SNP and Scottish Greens following defeat in the 2014 referendum on Scottish independence, and what have been the long-term consequences of these events. The chapter considers how to interpret these developments in the context of international research on party membership, establishing that the post-referendum surge was unprecedented in scale and pace. The chapter then outlines the details of the study, providing an account of the project’s aims, data, methods and analytical approach. To fully explain an exceptional example of political mobilisation, it is argued that the relationship between conventional parties and wider political and social movements must be understood.